Redox Reactions

• What is oxidation (in terms of electrons)?


  Loss of electrons
• What is reduction (in terms of electrons)?


  gain of electrons
• What is a redox reaction?

  A reaction in which both oxidation and reduction take place
• What is a useful phrase to help remember oxidation and reduction (but only in terms of electrons)?

  OIL RIG

  Oxidation is loss(of electrons)

  Reduction is gain(of electrons)
• What is a metal displacement reaction?

  A more reactive metal displaces a less reactive metal in a compound
• What is a half equation?

  An equation that shows the gain or lose of electrons of a single element in a reaction

  As an example, the half equation for the reduction of oxygen is:

  O2 + 4e- —> 2O^2-
• What is the half equation for the oxidation of magnesium?

  Mg -> Mg^2+ + 2e-
• In displacement reactions, are the metal ions reduced or oxidised?

  Reduced (they gain electrons)
• In displacement reactions, are the metal atoms reduced or oxidised?

  Oxidised (they lose electrons)
• Describe what is shown in ionic equations

  Only the particles that react and the products they form are shown- the ions that don’t change are ignored
• What do we call ions that are the involved in a chemical reaction?

  Spectator ions
• What is the ionic equation for this reaction: Mg + ZnCl2 —> MgCl2 + Zn

  The chloride ions don’t take part in the reaction so can be removed, this makes the equation: Mg + Zn —> Mg^2+ + Zn